Subjective effects of oral caffeine in formerly cocaine-dependent humans.
Eleven formerly cocaine-dependent (FCD) adults (mean 4 years in recovery) and 11 with no substance dependence history (ND) drank one cup of coffee (caffeine content 0, 50, or 100 mg) per hour for 5 h (for a total of 0, 250, or 500 mg caffeine) in a double-blind, randomized crossover procedure. Participants completed self-report scales before the first cup and 50 min after each cup. Caffeine did not increase cocaine-like effect or desire-for-cocaine ratings among the FCD subjects. Ratings of 'jittery' (P < 0.05) and 'anxious/tense/nervous' (P < 0.10) increased more with caffeine in the FCD group than among ND subjects. Self-report measures of caffeine reinforcement did not differ between FCD and ND groups. These results suggest that, among FCD adults, (a) caffeine does not produce cocaine-like effects, (b) caffeine reinforcement is neither greater nor lesser than that among ND adults, and (c) chronic cocaine use may induce sensitization to some effects of stimulants.
Liguori
A
A
Department of Psychiatry, University of Vermont, Burlington, USA.
Hughes
J R
JR
Goldberg
K
K
Callas
P
P
D000284:Administration, Oral; D000328:Adult; D001007:Anxiety / Q000209:etiology*; D002110:Caffeine / Q000008:administration & dosage / Q000009:adverse effects*; D019970:Cocaine-Related Disorders / Q000523:psychology*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006801:Humans; D008875:Middle Aged; D011795:Surveys and Questionnaires; D013997:Time Factors; D014202:Tremor / Q000209:etiology*
D002110:Caffeine